Reproducibility of Spectral-Domain Optical Coherence Tomography Total Retinal Thickness Measurements in Mice

UPMC Eye Center, Eye and Ear Institute, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
Investigative ophthalmology & visual science (Impact Factor: 3.4). 12/2010; 51(12):6519-23. DOI: 10.1167/iovs.10-5662
Source: PubMed


To test the reproducibility of spectral-domain optical coherence tomography (SD-OCT) total retinal thickness (TRT) measurements in mice.
C57Bl/6 mice were anesthetized, and three repeated volumetric images were acquired in both eyes with SD-OCT (250 A-scans × 250 frames × 1024 samplings), centered on the optic nerve head (ONH). The mice were repositioned between scans. TRT was automatically measured within a sampling band of retinal thickness with radii of 55 to 70 pixels, centered on the ONH by using custom segmentation software. The first volumetric image acquired in a given eye was used to register the remaining two SD-OCT images by manually aligning the en face images with respect to rotation and linear translation. Linear mixed-effects models were fitted to global and quadrant thicknesses, taking into account the clustering between eyes, to assess imprecision (measurement reproducibility).
Twenty-six eyes of 13 adult mice (age 13 weeks) were imaged. The mean global TRT across all eyes was 298.21 μm, with a mouse heterogeneity standard deviation (SD) of 4.88 μm (coefficient of variation [CV] = 0.016), an eye SD of 3.32 μm (CV = 0.011), and a device-related imprecision SD of 2.33 μm (CV = 0.008). The superior quadrant had the thickest mean TRT measurement (310.38 μm) and the highest (worst) imprecision SD (3.13 μm; CV = 0.010), and the inferior quadrant had the thinnest mean TRT (291.55 μm). The quadrant with the lowest (best) imprecision SD was in the nasal one (2.06 μm; CV = 0.007).
Good reproducibility was observed for SD-OCT retinal thickness measurements in mice. SD-OCT may be useful for in vivo longitudinal studies in mice.

Download full-text


Available from: Joel S Schuman
  • Source
    • "Spectral-domain optical coherence tomography (SD-OCT) scanning was adapted from the procedures described previously [41], [42]. Before each session, mice were anesthetized with an intraperitoneal injection of ketamine and xylazine to prevent large movements during SD-OCT image acquisition. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose To develop and characterize a mouse model with intraocular pressure (IOP) elevation after laser photocoagulation on the trabecular meshwork (TM), which may serve as a model to investigate the potential of stem cell-based therapies for glaucoma. Methods IOP was measured in 281 adult C57BL/6 mice to determine normal IOP range. IOP elevation was induced unilaterally in 50 adult mice, by targeting the TM through the limbus with a 532-nm diode laser. IOP was measured up to 24 weeks post-treatment. The optic nerve damage was detected by electroretinography and assessed by semiautomatic counting of optic nerve axons. Effects of laser treatment on the TM were evaluated by histology, immunofluorescence staining, optical coherence tomography (OCT) and transmission electron microscopy (TEM). Results The average IOP of C57BL/6 mice was 14.5±2.6 mmHg (Mean ±SD). After laser treatment, IOP averaged above 20 mmHg throughout the follow-up period of 24 weeks. At 24 weeks, 57% of treated eyes had elevated IOP with the mean IOP of 22.5±2.5 mmHg (Mean ±SED). The difference of average axon count (59.0%) between laser treated and untreated eyes was statistically significant. Photopic negative response (PhNR) by electroretinography was significantly decreased. CD45+ inflammatory cells invaded the TM within 1 week. The expression of SPARC was increased in the TM from 1 to 12 weeks. Histology showed the anterior chamber angle open after laser treatment. OCT indicated that most of the eyes with laser treatment had no synechia in the anterior chamber angles. TEM demonstrated disorganized and compacted extracellular matrix in the TM. Conclusions An experimental murine ocular hypertension model with an open angle and optic nerve axon loss was produced with laser photocoagulation, which could be used to investigate stem cell-based therapies for restoration of the outflow pathway integrity for ocular hypertension or glaucoma.
    Full-text · Article · Sep 2014 · PLoS ONE
  • Source
    • "Global and quadrant TRT outcome measurements were estimated by applying a linear mixed-effects statistical model. From their analyses, the authors reported that the mean global TRT was 298.21 µm [26]. Moreover, they showed the superior retina (310.38 µm) as being the thickest quadrant in comparison to the inferior (291.55 µm), nasal (296.52 µm) and the temporal (294.37 µm) zones. "
    [Show abstract] [Hide abstract]
    ABSTRACT: To report normative data for retinal thickness in wild-type C57BL/6 mouse utilizing a miniature SD-OCT system. THIRTY ADULT MICE (RANGE: 3-5 months) were anesthetized and secured into the Bioptigen Spectral Domain Ophthalmic Imaging System. Right eye SD-OCT images were standardized by centralizing the optic nerve head (ONH) prior to image acquisition. Global and quadrant total retinal thickness (TRT) values were measured from retinal nerve fiber layer to retinal pigment epithelial layer. Posterior segment analyses also included the outer retinal layer (ORL) and inner retinal layer (IRL). Further sublayer analyses of four layers from the ORL and three layers comprising the IRL were also performed. The overall mean±SD global TRT in a C57BL/6 mouse model was 204.41±5.19 µm. Quadrant mean TRT values were 204.85±5.81 µm inferiorly, 204.97±6.71 µm nasally, 205.08±5.44 µm temporally, and 202.74±4.85 µm superiorly. Mean±SD thickness for ORL, and IRL were 126.37±10.01 µm, and 107.03±10.98 µm respectively. The mean±SD estimates for the four layers of the ORL were 18.23±2.73 µm, 26.04±4.21 µm, 63.8±6.23 µm, and 19.22±4.34 µm. Mean±SD values for the three IRL sublayers were 27.82±4.04 µm, 59.62±6.66 µm and 19.12±3.71 µm. This study established normative values for the total retinal thickness and sublayer thickness for the wild-type C57BL/6 mice. Moreover, it provides a standard of retinal morphology, in a commonly used animal model, for evaluating therapeutic interventions and retinal disease pathophysiology.
    Full-text · Article · Jun 2013 · PLoS ONE
  • Source
    • "To avoid the potentially confounding effects of systemic hypertension (a risk factor for POAG [1]) observed in male but not female sGCα1−/− mice [31], [45], we included only female mice in our study that do not develop hypertension, even as they age [31]. Thickness of the retina and of the RNFL was measured using spectral-domain optical coherence tomography (SD-OCT), a technique previously shown to provide reproducible non-invasive measurements of RNFL thickness in mice [46]. Total retinal thickness was similar in sGCα1−/− and age-matched wild-type (WT) mice, regardless of their age (fig. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Primary open angle glaucoma (POAG) is a leading cause of blindness worldwide. The molecular signaling involved in the pathogenesis of POAG remains unknown. Here, we report that mice lacking the α1 subunit of the nitric oxide receptor soluble guanylate cyclase represent a novel and translatable animal model of POAG, characterized by thinning of the retinal nerve fiber layer and loss of optic nerve axons in the context of an open iridocorneal angle. The optic neuropathy associated with soluble guanylate cyclase α1-deficiency was accompanied by modestly increased intraocular pressure and retinal vascular dysfunction. Moreover, data from a candidate gene association study suggests that a variant in the locus containing the genes encoding for the α1 and β1 subunits of soluble guanylate cyclase is associated with POAG in patients presenting with initial paracentral vision loss, a disease subtype thought to be associated with vascular dysregulation. These findings provide new insights into the pathogenesis and genetics of POAG and suggest new therapeutic strategies for POAG.
    Full-text · Article · Mar 2013 · PLoS ONE
Show more